Stereotype printing plate



Nov; 29, 1932. 1 A WOOD 1,889,460

STEREOTYPE PRINTING PLATE Filed Nov. 18. 1931 Jake/275507 7167/3 14 726a 750:2

I, Ga -na Patented Nov. 29, 1932,

UNITED STATES PATENT. OFF-ICE HENRY A. WISE \VOOD, OF NEW YORK, N. Y-., ASSIGNOR T0 WOOD NEWSPAPER MIA- GI-IINERY CORPORATION, OF NEW YORK, N, Y., A CORPORATION OF VIRGINIA STEBEOTYPE PRINTING PLATE Application filed November 18, 1931. Serial No. 575,729.

The principal object of this invention is to provide a stereotype printing plate having adequate means for strengthening it and at the same time fewer surfaces that haverto be shaved on the back side than has been the case before.

Other objects and advantages of the invention will appear hereinafter.

Reference is to be had to the accompanying drawing, in which Fig. 1 is a longitudinal sectional View of a stereotype plate constructed in accordance with this invention;

Fig. 2 is a similar view showing the shavinr of the plate on the rear surface, and

ig. 3 is an end view of the parts shown in Fig. 2.

In the manufacture of stereotype plates, particularly those used on newspaper'printing presses, it is customary to cast the plate with ribs on the back or concave side. These ribs are finished off later to an accurate dimension by shaving the back.

The ribs are employed to lighten the plate and yet present a true surface which can be machined to enable the plate to fit the printing cylinder or other support. Ribs are used in full thickness plates also to reduce the power required for cutting out the inside of the plate to fit the cylinder. On account of the character of the metal used for stereotyping itiis desired to place these ribs quite close together to impart sufficient strength to the plate. However, any increase in the number of ribs puts added strain on the shavin mechanism.

ome of the difficulties above mentioned are avoided by this invention according to which a stereotype plate is cast with a large number of ribs, some of which are not long enough to be engaged by the shaving knife. Preferably, every alternate rib is short enough to just clear the shaving knife and therefore does not put any added strain on the shaving mechanism but does add to the strength of the plate.

Referring to the drawing a stereotype plate 10 is shown in the usual form, preferably, with the usual ribs 11 extending far enough inwardly, on the concave side of the face to engage the cylinder of the printing press. The alternate ribs 13 are not shaved but for all practical purposes, except that of rest-ing the plate against the cylinder, they function as the other ribs do.

In this way the strength of the plate is increased by adding to the number of ribs on the back and yet the power necessitated for shaving is not increased, but rather reduced. In fact the width and distances apart of these ribs can be so proportioned that the shaving requires even less power than heretofore. This invention is applicable to curved and flat plates.

Although I have illustrated and described only one form of the invention I am aware of the fact that modifications can be made therein by any person skilled in the art withnot wish to be limited in this respect but what I do claim is 1. As an article of manufacture, a stereotype printing plate having two series of ribs on the back, one series having their rear surfaces finished to fit the part of the machine to which the plate is applied and the other ribs being shorter than the first named ribs.

2. As an article of manufacture, a stereotype printing plate having two sets of strengthening ribs 0n the back, those of one set projecting beyond those of the other and shaved off to present a true surface for fitting the plate to a machine on which it is to be used.

3. As an article of manufacture, a concave stereotype printing plate having inner circumferential ribs on the concave back adapted to be shaved to thedesired, radius and another set of ribs, alternating with the first set,

and projecting from the back of the plate only far enough to insure that they will not be shaved off by the means used for shaving off the first set of ribs.

4. As an article of manufacture, a concave stereotype printing plate having on the back thereof two sets of ribs, alternating with each other, one set of ribs being long enough to be shaved oil to define a cylindrical surface and the other set of ribs projecting nearly to the said cylindrical surface but not extending to the cylindrical surface at which the other ribs are finished.

5. As an article of manufacture, a concave stereotype printing plate having two sets of ribs on the back, the ribs of one set being finished off to a true cylindrical surface and the ribs of the other set having their inner surfaces at a greater distance from the axis of the plate than the finished ribs, so that they will not be finished.

In testimony whereof I have hereunto afiixed my signature.

HENRY A. VISE WOOD- 

